Previously I wrote a post about well-known voice module of
DFPlayer Mini. Today I would like to write a post of advance chip, JQ8400. The main advantages of this chip are;
- Inquiry of the file name
- Inquiry of duration of the current audio
- Inquiry of playback duration
- Fast backward
- Fast forward, etc.
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Jq8400 Module
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JQ8400 module is a SOC solution that combines a 16bit MCU with an ADSP specialized in audio decoding. By using hardware decoding method, it ensures system stability, quality of sound, and small footprint matching requirements of embedded applications. For the flexibility of R&D, control commands can be sent via one-line mode or RS232 serial communication.
It adopts full duplex serial communication protocol: Baud rate 9600, 8-bit data, no parity and 1 stop bit.
Message Format
Starting Code + Command Code + Data Length + Data 1 – Data n + Checksum
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Starting Code: fixed as “AA” (in hex)
- Command Code: 01 – 26 (in hex)
- Data Length: respective data bytes in commands; length=1 stands for command only, no data.
- Checksum: The low byte of the sum of all the bytes before the checksum byte.
- Data format: high 8-bit first, low 8-bit second.
Communication Mechanism
Default power-on state is idle and listening for commands from MCU as a guest
The module will not initiate communication and a MCU must take initiative.
The TTL level of the serial port is 3.3V. Use a 1K ohm resistor if connecting with a 5V MCU.
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Jq8400 Module Pin Details
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Code
unsigned short df_wr[] = {0xAA,0,0,0,0,0};
void write_jq_cmd(char cmd, char data_h, char data_l, char len) //jq cmd data
{
char m;
Delay_ms(200);
df_wr[1]= cmd;
df_wr[2]= len;
df_wr[3]= data_h;
df_wr[4]= data_l;
df_wr[5]= data_h + data_l + len + df_wr[1] + 0xAA;
for (m=0; m<6; m++) {
Delay_ms(1);
if(len==0 && m==3) m=5; //(AA 02 00 AC) skip data_h data_l
if(len==1 && m==3) m=4; //(AA 18 01 03 C6) skip data_h
UART1_Write(df_wr[m]); //aa, cmd, len, dh, dl, sm
}
Delay_ms(10);
}
Usage
write_jq_cmd(0x02, 0,0, 0); //Play
write_jq_cmd(0x03, 0,0, 0); //Pause
write_jq_cmd(0x13, 0,27, 1); //Set volume to 27
write_jq_cmd(0x07, 0x00,0xF4, 2); //Play 244th track
write_jq_cmd(0x07, 0x01,0xF4, 2); //Play 500th track
write_jq_cmd(0x23, 0x00,0x0A, 2); //FF 10 seconds
